Utility companies provide single phase electric power to tenant facilities, such as apartment buildings or small commercial offices, through metering centers. Each metering center include a main disconnect means and overload protection, such as a circuit breaker or fused switch, and an individual electric meter for each tenant receiving electric service. The utility company supplies three phase power to a main service panel which houses the main disconnect and overload protection devices and a three phase feeder bus connected to the load side of the overload protection device. Each tenant's single phase power is taken from one of the A-B, A-C or B-C phase combinations of the three phase supply through individual meters housed in a meter module or meter stack which is added to the main service panel. It is important that the tenant loads be balanced between the A-B, A-C and B-C phase combinations to prevent overheating of conductors and for more efficient use of electricity. This has generally been accomplished by attempting to have an equal number of tenants on each of the A-B, A-C and B-C phase combinations. Due to cost, the most common method of load balancing has been to provide meter modules having two or more meter bases and a single phase bus which can be connected to one of the A-B, A-C or B-C phase combinations of the three phase feeder bus. In this configuration, at least one meter module is required for each of the A-B, A-C and B-C phase combinations in order to provide at least one meter connection in each of the A-B, A-C and B-C phase combinations. An alternative is to provide a meter module having a three phase bus with one meter base connected to each of the three A-B, A-C and B-C phase combinations. Meter modules of these types are taught in U.S. Pat. No. 3,628,097, which issued on Dec. 24, 1971, to Kobryner, and U.S. Pat. No. 4,041,358, which issued Aug. 9, 1977, to Donahue et al.
Neither of these configurations adequately address situations wherein the number of tenants is not a multiple of three or where changes in tenant usage or other events might significantly alter the load balance and require a rebalancing of the load based on calculated tenant loads. The meter bases in the devices described above are provided with factory made line connections which are not intended to be changed in the field and are generally difficult to work with. Therefore, the only method of rebalancing the load is to disconnect one or more tenants feeder cables from the load side of their meter bases and reconnect them to the load side of another meter base which is connected to a different one of the A-B, A-C or B-C phase combinations. This can be a difficult and time consuming job which requires the affected tenant or tenants to be without power for the time required to make the necessary load balancing changes. It would therefore be desirable to have a meter base module with provisions for easily and quickly changing the meter base line connections of any meter base in the module between any of the three A-B, A-C or B-C phase combinations.